The Shenzi 慎子 "Master Shen" is a philosophical treatise attributed to the Warring States period 戰國 (5th cent.-221 BCE) legalist philosopher Shen Dao 慎到 (ca. 350-275 BCE). Shen Dao came from the state of Zhao 趙 and was a teacher at the Jixia Academy 稷下 of the state of Qi 齊 during the reign of King Xuan 齊宣王 (r. 342-324). One of his collegues was the philosopher Tian Pian 田駢 (see Tianzi 田子).
In the universal history Shiji 史記 from the Han period 漢 (206 BCE-220 CE) it is said that the book of Shen Dao consisted of twelve "treatises" (lun 論). The imperial bibliographyYiwenzhi 藝文志 in the official dynastic historyHanshu 漢書 says that the Shenzhi was 42 chapters long. Of these, only 10 juan were left during the Tang period 唐 (618-907). It is known that a certain Teng Fu 滕輔 had written a commentary to the Shenzi. During the Song period 宋 (960-1279) two versions of the Shenzi were circulating, one in 37 chapters and 9 juan, and one in 5 chapters in 1 juan. Taken together these two parts might have been identical with the original book (37 plus 5 makes 42, as the scholar Jin Dejian 金德建 remarked). The private bibliography Zhizhai shulu jieti 直齋書錄解題 says that the book was five chapters long, which were certainly only a fragment of the whole original text. In contrast to this statement, the official bibliography Chongwen zongmu 崇文總目 includes the 37-chapter version. After the Song period this larger part was lost, and only the fragmentary small version survived. Except the five chapters, there are two further chapters surviving in the collection Qunshu zhiyao 群書治要. All seven chapters were put together and found their way into Qian Xizuo's 錢熙祚 collectaneaShoushange congshu 守山閣叢書. Some 10 fragments are surviving as quotations in other books. During the late Ming period there was a version in circulation, divided into inner and outer chapters, with 89 paragraphs, but this text was a forgery by a certain Shen Maoshang 慎懋賞. Although the Shenzi includes "miscellaneous" thoughts of a very large ideological spectrum (the compilers of the imperial collectanea Siku quanshu 四庫全書 therefore classified it as a "miscellaneous treatise", zajia 雜家), it is an early document of legalist thinking which stressed the importance of ruling by law and by strengthening the position of the ruler. Shen Dao was criticised by Xun Kuang 荀況 (Xunzi 荀子) for his not stressing the importance of employing competent ministers (xian 賢) – because only with the support of able persons the ruler would be strong enough in the legalist sense. Laws alone would not suffice. Shen Dao's ideas were, in Xunzi's words, "unable to govern a country with" (bu ke yi jing guo ding fen 不可以經國定分).
The preserved version of the Shenzi is also to be found in the collectanea Zihui 子匯, Zhuzi jicheng 諸子集成 and Siku quanshu 四庫全書.